This invention relates generally to a packaged terminal air conditioning unit. More specifically, the present invention relates to an apparatus and method for attenuating the noise generated by the indoor blower of a packaged terminal air conditioner (PTAC).
Air conditioning units which are commonly used for light commercial applications such as hospitals, hotels/motels, apartments, and offices are of the type known as a packaged terminal air conditioner. These packaged terminal air conditioners extend through the wall of the enclosure or room and normally have a condensing section located in communication with the outdoor air for discharging heat energy. An evaporator section is provided in communication with the enclosure air for conditioning said air as it is drawn through the unit. Although air conditioner units are described herein, PTAC units may also be heat pumps or the like.
Generally, a PTAC unit is located low on a wall and has a sloped air discharge opening with a grille to disperse conditioned air throughout the entire room. However, the sloped discharge opening of the unit is a line-of-sight noise path from the fan wheel to the occupant of the space. Sound insulating material can be used in the casing of the PTAC unit, but this does not reduce the noise generated by the fan wheel and propagated through the discharge opening. It is desirable, however, to reduce the effect of this direct line-of-sight noise path. To accomplish this, either a redesign of PTAC units is necessary, or the noise source of the PTAC units must be muffled by a retrofittable silencer.